//=============================================================================
// System  : MatchKit
// File    : Capture.cs
// Author  : Fabio Bussu  (matchkit@fabiobussu.it)
// Updated : 04/16/2013
// Note    : Copyright 2013, Fabio Bussu, All rights reserved
//
// This code is published under the Microsoft Public License (Ms-PL). A copy
// of the license should be distributed with the code.  It can also be found
// at the project website: http://matchkit.codeplex.com. This notice, the
// author's name, and all copyright notices must remain intact in all
// applications, documentation, and source files.
//
// Version     Date     Who  Comments
// ============================================================================
// 1.0.0.0  04/16/2013   FB  First draft
//=============================================================================
using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Text;

namespace MatchKit
{
	/// <summary>
	/// Captures a substring from a <see cref="T:MatchKit.MatchContext"/>.
	/// </summary>
	/// <threadsafety static="true" instance="false" />
	/// <serialization binary="true" contract="true" />
	/// <remarks>
	/// The constructor saves the current context position as starting point. Invoking ToString() 
	/// returns a substring to the current context position.
	/// </remarks>
	/// <conceptualLink target="0a06b2a9-5f58-409a-ba62-639cfd77bca7" />
	#if DC
	[DataContract]
	#endif
	#if SZ
	[Serializable]
	#endif
	public sealed class Capture
	{
		#if DC
		[DataMember]
		#endif
		private MatchContext _context;
		#if DC
		[DataMember]
		#endif
		private int _index;

		/// <summary>
		/// Initializes a new instance of the <see cref="T:MatchKit.Capture"/> class.
		/// </summary>
		/// <param name="context">The match context. This value cannot be null.</param>
		public Capture(MatchContext context)
			: this(context, false)
		{
		}

		/// <summary>
		/// Initializes a new instance of the <see cref="T:MatchKit.Capture"/> class.
		/// </summary>
		/// <param name="context">The match context. This value cannot be null.</param>
		/// <param name="includeCurrentCharacter">Value specifying whether to include in the capture the current context character.</param>
		public Capture(MatchContext context, bool includeCurrentCharacter)
		{
			if (context == null)
				throw new ArgumentNullException("context", "context cannot be null");
			_context = context;
			_index = context.Index;
			if (!includeCurrentCharacter)
				_index++;
		}

		/// <inheritdoc />
		public override string ToString()
		{
			return _context.TargetText.Substring(_index, _context.Index - _index);
		}
	}
}
